Copper(II) complexes of tetradentate thioether-oxime ligands
摘要:
Two dinuclear copper(II) thioether-oxime complexes ([Cu(DtdoH)](2)(ClO4)(2) and [Cu(DtudH)](2)(ClO4)(2) (.) 2CH(3)OH) have been synthesized. [Cu(DtdoH)]2(ClO4)2 reacted with excess BF3 (.) OEt2 to yield [Cu(Thyclops)]ClO4, a BF2+-macrocyclized di-oxime. [Cu(DtdOH)](2)(ClO4)(2) and [Cu(DtudH)](2)(ClO4)(2) (.) 2CH(3)OH are the first representatives of copper(H) thioether oximes which exhibit the classical out-of-plane oximate oxygen-metal dimer structure. [Cu(DtdoH)](2)(ClO4)2 and [Cu(Thyclops)]ClO4 have been structurally characterized by single-crystal X-ray diffraction. The geometry about each copper(H) in [Cu(DtdoH)](2)(ClO4)2 is a distorted square pyramid (tau = 0.14). The average copper-nitrogen(oxime) bond length is 1.984 angstrom longer (similar to 0.03 angstrom) than the average copper-nitrogen(oxime) bonds in copper(II) bis-glyoximates. The geometry of [Cu(Thyclops)]ClO4 reveals an almost perfect square pyramid (tau = 0.03) of N2S2O donors. Solution, cryogenic glass, and powder ESR spectra show a typical axial pattern, except for the powder spectrum of [Cu(DtudH)](2)(ClO4)2 (.) 2CH(3)OH which displays a small rhombic distortion. Variable-temperature magnetic susceptibility measurements indicate very weak ferromagnetic interactions in [Cu(DtdoH)](2)(ClO4)2, where J = +0.52 cm(-1) and very weak antiferromagnetic interactions in [Cu(DtudH)](2)(ClO4)2 (.) 2CH(3)OH, where J = -0.59 cm(-1). Electrochemical measurements reveal that the mixed thioether-oxime coordination environment tends to stabilize Cu(II), as all electrochemical reductions were quasi-reversible or irreversible. [Cu(thyclops)]ClO4 is more oxidizing than [Cu(DtdoH)](2)(ClO4)2 by 0.14 V. (c) 2005 Elsevier B.V. All rights reserved.
Copper(II) complexes of tetradentate thioether-oxime ligands
作者:Michael J. Prushan、Anthony W. Addison、Raymond J. Butcher、Laurence K. Thompson
DOI:10.1016/j.ica.2005.04.038
日期:2005.8
Two dinuclear copper(II) thioether-oxime complexes ([Cu(DtdoH)](2)(ClO4)(2) and [Cu(DtudH)](2)(ClO4)(2) (.) 2CH(3)OH) have been synthesized. [Cu(DtdoH)]2(ClO4)2 reacted with excess BF3 (.) OEt2 to yield [Cu(Thyclops)]ClO4, a BF2+-macrocyclized di-oxime. [Cu(DtdOH)](2)(ClO4)(2) and [Cu(DtudH)](2)(ClO4)(2) (.) 2CH(3)OH are the first representatives of copper(H) thioether oximes which exhibit the classical out-of-plane oximate oxygen-metal dimer structure. [Cu(DtdoH)](2)(ClO4)2 and [Cu(Thyclops)]ClO4 have been structurally characterized by single-crystal X-ray diffraction. The geometry about each copper(H) in [Cu(DtdoH)](2)(ClO4)2 is a distorted square pyramid (tau = 0.14). The average copper-nitrogen(oxime) bond length is 1.984 angstrom longer (similar to 0.03 angstrom) than the average copper-nitrogen(oxime) bonds in copper(II) bis-glyoximates. The geometry of [Cu(Thyclops)]ClO4 reveals an almost perfect square pyramid (tau = 0.03) of N2S2O donors. Solution, cryogenic glass, and powder ESR spectra show a typical axial pattern, except for the powder spectrum of [Cu(DtudH)](2)(ClO4)2 (.) 2CH(3)OH which displays a small rhombic distortion. Variable-temperature magnetic susceptibility measurements indicate very weak ferromagnetic interactions in [Cu(DtdoH)](2)(ClO4)2, where J = +0.52 cm(-1) and very weak antiferromagnetic interactions in [Cu(DtudH)](2)(ClO4)2 (.) 2CH(3)OH, where J = -0.59 cm(-1). Electrochemical measurements reveal that the mixed thioether-oxime coordination environment tends to stabilize Cu(II), as all electrochemical reductions were quasi-reversible or irreversible. [Cu(thyclops)]ClO4 is more oxidizing than [Cu(DtdoH)](2)(ClO4)2 by 0.14 V. (c) 2005 Elsevier B.V. All rights reserved.